Drawing instrument



Aug. 27, 1940. r c. M. SUFFICH 2,212,703

DRAWING INSTRUMENT Filed Feb. 9, 1938 Patented Aug. 27, 1940 UNITEDSTATES rem OFFICE- 3 Claims.

The object of my invention is to provide an improved drawing instrumentof extremely simple character, which may be used by draftsmen to easilyand "conveniently draw a series of parallel lines; the invention beingparticularly meritorious in that with it a plurality of parallelirregular curved lines may be drawn quickly and accurately. Theseparallel curved lines may be used to an advantage as a guide on which toplace lettering.

It is well known to those skilled in this art that it is time consuming,tedious and a dimcult task to draw a series of accurately spacedirregular curved lines. With my improved instrument, this may be donewith accuracy and dispatch simply by properly operating the instrumentalong the straight or curved edge of any of the drafting instruments nowused by draftsmen in connection with proper positioning of a scribing ormarking element, such as a pencil, upon the instrument.

Other objects and advantages of the invention will be apparent duringthe course of the following detailed description.

In the accompanying drawing, forming a part of this specification andwherein similar reference characters designate corresponding partsthroughout the several views,

Figure 1 is a plan view of the instrument.

Figure 2 is a section of the same.

Figure 3 is a plan view of the instrument in use on the top edge of a Tsquare.

Figure 4 shows the instrument in use on a lower edge of a T square.

Figure 5 shows the instrument applied to the upper edge of a section ofa draftsmans scroll.

Figure 6 shows the instrument applied to the lower edge of a section ofa draftsmans scroll.

In the drawing the letter A designates the instrument, hereinafterdesignated as a disk, which may be made of pyroxylin, synthetic resin,wood, metal, fibre, hard rubber, or any approved material such as thevarious angles, irregular curves and templets of engineers and draftsmenare made. In the preferred instance, it is of transparent material, suchas synthetic resin or pyroxylin and is disk shaped and of uniformthickness. This instrument may be made in different sizes vto suit thepurpose of the engineer or draftsman, as is the common practice inmaking draftsmans instruments. In the preferred instance, the shape ofthe instrument forming the subject matter of this invention, is in theshape shown in the drawing, i. e., a disk, but this shape may bedeparted from without departing from the broad conception of theinvention. The only demand is that the instrument be substantially roundso that it will follow closely the shape of the drafting instrumentwhich guides it.

The disk A has a series of lines I printed or etched thereon, whichradiate from the central point of the disk, thus dividing the disk intosectors. Each of the sectors of the disk has therein a series ofopeningswhose arangement and function will be described in detail. The 1openings in the disk A are made tapered, as

- shown in Figure 2, so that the point of a lead pencil D may be easilyinserted into the desired opening. The openings in each sector of thedisk are of different arrangement so that a L ing distances. The same istrue of the holes in the disc designated as 5. In other words, in eachsector of the disk the only holes that correspond are those designatedas 2, While those designated as 3 to 5 inclusive are in differentarrangement in that they have various distances from the edge of thedisk A.

While I have shown only 4 openings or holes in each sector of the diskA, the number of openings in each sector may be materially increased,the only limitation on the number of openings in each sector is that noopenings should be closer to the center of the disk than one-half thedistance of the radius of the disk. This is because the instrument willhave a tendency to turn, rather than slide, if the opening used is muchbeyond the limit indicated above. Each sector of the disk should haveprinted or etched thereon figures or symbols, designating thearrangement of the opening in that particular sector, so that the userof the instrument can ascertain at a glance the arrangement of theparticular openings he desires to use. Of course, the openings in eachsector of the disk could be arranged in a line, as opposed to thegrouping shown, thus accommodating a larger number of different openingson the same size disk.

While I show in the drawing, forming a part of this application, thedisk lined oii in 8 sectors, the number of sectors can be materiallyincreased, the only disadvantage in such increase of sectors being thatthe user of the instrument will find it more difficult to ascertain at aglance the desired group of openings that he wishes to use.

The object of the invention is to permit the easy scribing of parallellines, which parallel lines may be used for the base on which to letter,without the necessity of shifting the other drafting instrument used incombination with this instrument. The other drafting instrument may be aT square like that shown in Figures 3 and 4, or a draftsmans scroll likethat shown in Figures 5 and 6.

To use the drawing instrument forming the subject matter of myinvention, the draftsman selects the group of openings which will makethe desired spaced parallel lines wanted. Then having selected a '1square, curve or templet, hereinafter called a base, which base has anedge that corresponds in shape to the parallel lines desired, he placesthe base having the desired edge on paper in a position so that thelines to be formed will be made in the place desired. Then after placingthe drawing instrument of this invention either above or below thedesired edge of the base, he places a pencil in one of the openings inthe sector closest to the base and moves the drawing instrument thedesired distance, thus forming a line parallel to the base. Naturallythe number of lines thus formed is governed by the number of times thisoperation is performed, and their position in relation to each other bythe openings selected.

The disk, on account of its shape and hard material of which it is made,slides and easily follows the contour of any of the well-known draftinginstruments, as will be seen by looking at Figures 5 and 6 of thedrawing wherein the disk is on the upper and lower edges of a draftsmansscroll. It is evident that the drawing instrument of my invention,because of its shape, will follow abrupt curves more closely and moreaccurately than does the square or rectangular drawing instrumentheretofore used for the same purpose.

I claim:

1. A drawing instrument in the form of a disk, the plane surface of saiddisk being marked to designate sectors, openings grouped in each sectorentirely around and adjacent the peripheral edge of the disk, none ofsaid openings being closer to the center of the disk than one-half ofthe radius.

2. A drawing instrument of the type employed with a curved edge base andadapted to be slid along said base, comprising a disk with openingstherein, said openings being arranged in like groups around theperiphery of the disk, the corresponding openings of the diiferentgroups, except the opening forming the base of the groups of openings,being spaced from the peripheral edge of the disk in unlike distanceswith none of the openings of the several groups being closer to thecenter of the disk than one-half of the radius.

3. A drawing instrument comprising a circular disk with openings thereinarranged in groups entirely around the same adjacent the peripherythereof, the surface of the disk in the center area being entirely voidof openings.

CORNELIUS M. SUFFICI-I.

